Examination chair base



FIG. 1 is a front perspective view of the examination chair base withportions thereof in phantom representing environmental matter which isnot part of the claimed invention;

FIG. 2 is a top view of the examination chair base as shown in FIG. 1;

FIG. 3 is a left side view of the examination chair base as shown inFIG. 1 with the right side being a mirror image of the left side;

FIG. 4 is a rear view of the examination chair base as shown in FIG. 1;

FIG. 5 is a front view of the base as shown in FIG. 1; and,

FIG. 6 is a bottom view of the examination chair base as shown in FIG.1.

The ornamental design for an examination chair base, as shown anddescribed.